Efficacy of a single dose of cefazolin as a prophylactic antibiotic in primary arthroplasty

We analyzed the wound infection rate of 1,367 primary total hip and knee arthroplasties performed between 1991 and 1999. Two hundred and fifteen arthroplasties were performed with 3 doses (3 x 750 mg) of cefuroxime, and 1,152 arthroplasties were performed with a single preoperative dose (1 x 1 g) of cefazolin as antimicrobial prophylaxis. All wound infections that occurred within 2 years of the index surgery were analyzed. The deep wound infection rate of total hip arthroplasty was 1.1% (95% confidence interval [CI], 0%-3.3%) in the cefuroxime group and 1.1% (95% CI, 0%-2.2%) in the cefazolin group (Fisher's exact test, P = 1.0). The deep wound infection rate of total knee arthroplasty in the cefuroxime group (1.6%; 95% CI, 0%-3.8%) was not significantly different from the cefazolin group (1.0%; 95% CI, 0.3%-1.7%) (Fisher's exact test, P =.63). We concluded that a single dose (1 g) of cefazolin given at anesthetic induction offered similar protection to 3 doses (3 x 750 mg) of cefuroxime in preventing infection in primary total joint arthroplasty.     

Practicing cementing technique with a toy: Play-Doh

Cementing technique has direct impact on the longevity of a total hip arthroplasty, and the proper technique can only be acquired by practice. Using acrylic bone cement to practice cementing technique in a bioskill workshop is expensive and can cause occupational hazards. In this article, we describe a toy that can replace acrylic bone cement in a bioskill workshop. Play-Doh (Hasbro Inc, Pawtucket, RI) is an inexpensive, reusable and non-toxic modeling toy that mimics the doughy phase of acrylic bone cement.     

Prognosis after hepatic resection for stage IVA hepatocellular carcinoma: a need for reclassification

OBJECTIVE: To evaluate whether the prognosis of the four categories of patients with hepatocellular carcinoma (HCC) classified as stage IVA in the tumor-node-metastasis (TNM) classification of the International Union Against Cancer (UICC) is homogeneous. SUMMARY BACKGROUND DATA: Hepatic resection has been proposed as the treatment of choice for patients with TNM stage IVA HCC, which consists of four different categories. It is unknown whether the prognosis of the four categories of patients is homogeneous. METHODS: Clinicopathologic and follow-up data of 106 patients with resection of stage IVA HCC from 1989 to 2000 were prospectively collected. Survival results of the four categories of stage IVA patients were compared. RESULTS: Among stage IVA patients, survival was significantly worse in those with tumors involving a major branch of the portal or hepatic veins than in those with tumors invading adjacent organs, bilobar multiple tumors, or perforated visceral peritoneum. There were no significant differences in survival among the latter three groups. By Cox regression analysis, invasion of the portal or hepatic veins and presence of cirrhosis were independent adverse prognostic factors of overall survival among stage IVA patients, and invasion of the portal or hepatic veins was the only significant adverse prognostic factor of disease-free survival. CONCLUSIONS: The prognosis of the four categories of patients with stage IVA HCC under the current UICC TNM staging was not homogeneous. A refined classification of stage IV HCC is needed to take into consideration the worse prognosis associated with tumor invasion of a major branch of the portal or hepatic veins.     

Graft injury in relation to graft size in right lobe live donor liver transplantation: a study of hepatic sinusoidal injury in correlation with portal hemodynamics and intragraft gene expression

OBJECTIVE: To investigate the degree and mechanism of hepatic sinusoidal injury in different graft sizes in right lobe live donor liver transplantation (LDLT). SUMMARY BACKGROUND DATA: Liver grafts from living donors are likely to be small-for-size for adult recipients. Graft injury after reperfusion is common, but the mechanism and degree of injury remain unclear. The hepatic sinusoidal injury in different graft sizes and its relationship with portal hemodynamics and intragraft gene response at the early phase after reperfusion have not been studied in right lobe LDLT. METHODS: From May 2000 to November 2001, 40 adults receiving right lobe LDLT had portal pressure measured continuously before and after reperfusion. Liver biopsies were taken before and after reperfusion for detection of vasoregulatory genes (endothelin-1 and endothelial nitric oxide synthase) and heat shock genes (heat shock protein 70 and heme oxygenase-1), and electron microscope examination. Blood samples from the portal vein and suprahepatic inferior vena cava were taken for the measurement of plasma nitric oxide level. RESULTS: The recipients were grouped according to the ratio of graft weight to estimated standard liver weight: group 1 (n = 10), less than 40%; group 2 (n = 21), 40% to 60%; and group 3 (n = 9), more than 60%. The portal pressures recorded after reperfusion in group 1 were significantly higher within 30 minutes of reperfusion than those in groups 2 and 3. After reperfusion, the intragraft endothelin-1 mRNA level in group 1 increased by 161% of the basal level but decreased by 31.5% and 62% of the basal level in groups 2 and 3, respectively. The intragraft mRNA level of heme oxygenase-1 in groups 1 and 2 decreased by 75.5% and 25.3% of the basal level respectively but increased by 41% of basal level in group 3. The intragraft protein level of heat shock protein 70 decreased by 50 ng/mL after reperfusion in group 1 but increased by 12.4 ng/mL and 0.6 ng/mL in groups 2 and 3, respectively. The portal vein plasma nitric oxide level decreased more significantly after reperfusion in group 1 than in group 2. Electron microscope examination of liver biopsies in group 1 showed tremendous mitochondrial swelling as well as irregular large gaps between the sinusoidal lining cells. There were two hospital deaths in group 1 and none in the other two groups. CONCLUSIONS: Patients implanted with grafts less than 40% of standard liver weight suffered from transient portal hypertension early after reperfusion. The phenomenon was accompanied by intragraft upregulation of endothelin-1 and ultrastructural evidence of sinusoidal damage. The transient portal hypertension after reperfusion, subsequent endothelin-1 overexpression, and plasma nitric oxide level reduction, together with downregulation of heme oxygenase-1 and heat shock protein 70, may account for the small-for-size graft injury.     

Castleman disease of the pleura: experience with eight surgically proven cases

BACKGROUND: Castleman disease of the pleura is unusual, and we present our experience with eight surgically proven cases. METHODS: Between 1980 and 2002, 8 patients (7 women and 1 man; age range, 20 to 53 years; mean, 26.5 years) with surgically proven, pleural Castleman disease (six hyaline vascular type, one plasma cell type, and one mixed type) were encountered. Their clinical, imaging, and surgical findings were reviewed. RESULTS: Five patients were asymptomatic, 1 had dyspnea, 1 had cough, and 1 experienced chest discomfort. Chest radiography showed a well-circumscribed interlobar, cardiophrenic, or paraaortic mass in 6 patients, a massive effusion in 1, and a focal diaphragmatic bulge in 1. Six tumors showed varying degrees of contrast enhancement (10 to 95 HU; mean, 46 HU) on computed tomography. Three cases appeared as well-defined, heterogeneously hyperintense pleural masses on magnetic resonance imaging. The masses varied in size from 3 to 10 cm (mean, 5.2 cm). Five masses greater than 5 cm had prominent pleural arterial blood supply and severe adhesions requiring thoracotomy and resection of nearby structures for radical tumor excision. Blood loss from patients varied between 100 and 850 mL (mean, 620 mL). No tumor recurrence was noted during follow-up (range, 1 to 16 years; mean, 6.5 years). CONCLUSIONS: Pleural Castleman disease predominately affects young women and manifests as a well-circumscribed mass with a varying degree of contrast enhancement on computed tomography and heterogeneity on magnetic resonance imaging. Tumors greater than 5 cm have profuse pleural blood supplies and severe adhesion necessitating open thoracotomy and resection of neighboring structures. Radical resection can produce a satisfactory outcome.     

Full weight bearing after non-cemented total hip replacement is compatible with satisfactory results

Two matched groups of 29 patients underwent hydroxyapatite-coated non-cemented total hip replacement. One group was started on immediate protected-weight-bearing walking and the other group was started on immediate full-weight-bearing walking. They were followed up regularly for 2 years. They were assessed with Harris hip score clinically and Engh's criteria of osteo-integration radiographically. No difference was found between the two groups. All patients had excellent clinical outcome after hip replacement, and all femoral stems were stable radiographically. Patients can walk with full weight bearing safely immediate after hydroxyapatite-coated non-cemented total hip replacement.     

Gastric reflux and pulmonary aspiration in anaesthesia

Although aspiration is a relatively rare event during anaesthesia, it represent an important cause of anaesthesia related mortality and also of ventilator associated pneumonia in intensive care unit. The incidence of aspiration is markedly increased after trauma owing to the risk of recent ingestion of food, depression of consciousness and airways reflexes, and gastric stasis induced by raised sympathoadrenal tone. The factors which contribute to the likelihood of aspiration include the urgency of surgery, airways problems, inadequate depth of anaesthetic, use of the lithotomy position, gastrointestinal problems, depressed consciousness, increased severity of illness and obesity. Factors that predispose to aspiration pneumonia are: a gastric content with a pH less than 2.5 and a gastric volume of 0.4 ml kg-1; a reduction in lower oesophageal sphincter tone; a reduction of upper oesophageal sphincter tone and a not coordination between the pharyngeal muscle and the upper oesophageal sphincter tone during swallowing; and a depression of protective airway reflexes. Methods to minimize regurgitation and aspiration involve control of gastric contents (preoperative starvation is the method universal accepted), application of cricoid pressure and control of the airways.